Impact of mesorectal extranodal tumor deposits in magnetic resonance imaging on outcome of rectal cancer patients

AIM

Mesorectal extranodal tumor deposits (TDs) are identified in many rectal cancers. Their radiological features differ from metastatic lymph nodes, and they can be detected with magnetic resonance imaging (MRI). The purpose of this study was to determine the prevalence of rectal cancer TDs detected with MRI and their impact on overall (OS), cancer-specific (CSS), and disease-free survival (DFS) and the local recurrence rate.

METHOD

In this retrospective cohort study, we screened all 525 consecutive rectal cancer patients who underwent surgery during 2017-2018 in a tertiary center. Patients with synchronous metastases or who had not undergone MRI were excluded. We analyzed the OS, CSS, and DFS as well as local recurrences.

RESULTS

Of the 480 included patients, TDs were detected in the images of 81 (16.9 %). Extramural venous invasion (EMVI) and TDs were frequently found together (n = 50, 61.7 % of all cases with TDs). The presence of TDs alone [hazard ratio (HR) 1.66 (1.03-2.68)] or TDs and/or EMVI [HR 1.63 (1.01-2.62)] were risk factors for adverse DFS in multivariate Cox regression analysis. The OS and CSS rates were poorer among patients with TDs compared to those without, p = 0.009 and p < 0.001, respectively. TDs were also a risk factor for local recurrence in the univariate analysis.

CONCLUSIONS

TDs detected with imaging are a risk factor for impaired DFS and associated with impaired CSS and OS of rectal cancer patients and should be taken into consideration in clinical decision-making.

Microbiota and mucosal gene expression of fecal microbiota transplantation or placebo treated patients with chronic pouchitis

Altered microbiota and impaired host immune function have been linked to the pathogenesis of pouchitis. We used 16S rRNA gene sequencing and RNA sequencing data from a previous randomized clinical trial (RCT) on fecal microbiota transplantation (FMT) therapy in 26 chronic pouchitis patients with one-year follow-up. We analyzed changes in both luminal and mucosal microbiota composition, as well as in host mucosal gene expression to gain insights into the host-microbiota interactions possibly underlying clinical outcomes of the patients. Antibiotic type and pattern of use were significant drivers of the luminal microbiota at baseline. Differential gene expression analysis indicated transition from ileal to colonic gene expression in the pouch, and upregulation in inflammation- and immune system-related pathways in the pouch. At 4 weeks, the non-relapsed FMT patients had a lower microbiota dissimilarity to the donor than the non-relapsed placebo patients (p = .02). While two FMT-treated patients showed a shift toward the donor's microbiota during the one-year follow-up, the overall FMT microbiota modulation effect was low. Patient's luminal and mucosal microbiota profiles were unstable in both FMT and placebo groups. Expression of the chemokine receptor CXCR4 was downregulated at 52 weeks compared to the baseline in the non-relapsed patients in both FMT and placebo groups. Microbiota modulation by FMT seems to be low in this patient group. The microbiota composition or alterations did not explain the relapse status of the patients. Some evidence for remission-related host gene expression pattern was found; specifically, CXCR4 expression may have a role in sustained remission.

The ability of magnetic resonance imaging to predict lymph node metastases and the risk of recurrence in rectal cancer

AIM

This study aimed to examine the diagnostic accuracy and prognostic value of magnetic resonance imaging (MRI) detected lymph nodes in rectal cancer.

METHOD

We evaluated 806 rectal cancer patients consecutively operated on between 2015 and 2018 at Helsinki University Hospital. In total, 485 patients met the inclusion criteria of presenting with stage I-III disease and were intended for curative treatment at the time of diagnosis. The effect of MRI-detected clinical lymph node status (cN) on cumulative overall survival (OS), disease-specific survival (DSS) and disease-free survival (DFS) was calculated using the Kaplan-Meier analysis.

RESULTS

Negative predictive value (NPV) of MRI-lymphnode negativity was 74.8%. Positive predictive value of lymph node metastasis was only 48.6%. In the Kaplan-Meier survival analysis, OS (p = 0.989), DSS (p = 0.911), and DFS (p = 0.109) did not significantly differ according to MRI nodal status. However, cumulative disease-free survival significantly (p < 0.001) differed according to the histopathological lymph node metastasis status (pN).

CONCLUSIONS

MRI detected lymph node positivity appears insufficiently precise and cannot predict disease recurrence or survival. Therefore, it should not serve as an independent risk factor when considering neoadjuvant treatment options for rectal cancer patients.

The prognostic value of extramural venous invasion in preoperative MRI of rectal cancer patients

AIM

This study aimed to examine the prognostic value of extramural venous invasion observed in preoperative MRI on survival and recurrences.

METHOD

In total, 778 rectal cancer patients were evaluated in multidisciplinary meetings in Helsinki University Hospital during the years 2016-2018. 635 patients met the inclusion criteria of stage I-III disease and were intended for curative treatment at the time of diagnosis. 128 had extramural venous invasion in preoperative MRI.

RESULTS

The median follow-up time was 2.5 years. In a univariate analysis extramural venous invasion was associated with poorer disease-specific survival (hazard ratio [HR] 2.174, 95% CI 1.118-4.224, P = 0.022), whereas circumferential margin ≤1 mm, tumour stage ≥T3c or nodal positivity were not. Disease recurrence occurred in 17.3% of the patients: 13.4% had metastatic recurrence only, 1.7% mere local recurrence and 2.2% both metastatic and local recurrence. In multivariate analysis, extramural venous invasion (HR 1.734, 95% CI 1.127-2.667, P = 0.012) and nodal positivity (HR 1.627, 95% CI 1.071-2.472, P = 0.023) were risk factors for poorer disease-free survival (DFS). Circumferential margin ≤1 mm was a risk factor for local recurrence in multivariate analysis (HR 5.675, 95% CI 1.274-25.286, P = 0.023).

CONCLUSION

In MRI, circumferential margin ≤1 mm is a risk factor for local recurrence, but the risk is quite well controlled with chemoradiotherapy and extended surgery. Extramural venous invasion instead is a significant risk factor for poorer DFS and new tools to reduce the systemic recurrence risk are needed.

Fecal Microbiota Transplantation in Chronic Pouchitis: A Randomized, Parallel, Double-Blinded Clinical Trial

BACKGROUND

In ulcerative colitis, a pouchitis is the most common long-term adverse effect after proctocolectomy and ileal pouch-anal anastomosis. Approximately 5% of patients develop chronic antibiotic-dependent or antibiotic-refractory pouchitis without any effective treatment. The aim of this trial was to investigate the efficacy and safety of fecal microbiota transplantation in the treatment of chronic pouchitis.

METHODS

This was a single-center, double-blinded, parallel group trial comparing donor fecal microbiota transplantation with placebo (autologous transplant) in chronic pouchitis. Twenty-six patients were recruited at the Helsinki University Hospital between December 2017 and August 2018 and were randomly allocated a 1:1 ratio to either donor fecal microbiota transplantation or placebo. The protocol included 2 transplantations into the pouch on weeks 0 and 4, and patients were followed up for 52 weeks.

RESULTS

Nine patients in the intervention group and 8 patients in the placebo group relapsed during the 52-week follow-up, and the relapse-free survival did not differ between the groups (P = 0.183, log-rank; hazard ratio, 1.90 [95% confidence interval, 0.73-4.98; P = 0.190]). In the subgroup analysis of patients using continuous antibiotics before the study, the relapse-free survival was shorter in the intervention group (P = 0.004, log-rank; hazard ratio, 13.08 [95% confidence interval, 1.47-116.60; P = 0.021]). No major adverse effects were reported.

CONCLUSIONS

The fecal microbiota transplantation treatment regime used in our study was not effective in the treatment of chronic pouchitis. The safety profile of fecal microbiota transplantation was good.

CLINICALTRIALS.GOV IDENTIFIER

NCT03378921.

Dysplasia in the mucosal biopsy specimen is still a warning sign of cancer in ulcerative colitis

OBJECTIVES

Patients with ulcerative colitis are at increased risk for colorectal cancer, especially at younger ages. Our aim was to determine, in our patient cohort, the clinicopathological features, incidence, and prognosis of ulcerative colitis-associated colorectal cancer.

MATERIALS AND METHODS

A single-center, population-based study including all 1241 patients with ulcerative colitis who underwent surgery in Helsinki University Hospital, 1991-2018. All data were from medical records, collected retrospectively.

RESULTS

In total, 71 patients with ulcerative colitis-associated cancer were operated on in Helsinki University Hospital during 1991-2018; 108 patients undergoing surgery during 2002-2018 showed dysplasia in the surgical specimen. Cancer was diagnosed preoperatively in 47 patients (66.2%). Ten patients (14.1%) had synchronous colorectal cancer, and 24 (33.8%) had synchronous dysplasia. The incidence of colorectal cancer has not changed during the study period (p = .113). Overall survival was 71.8%, and the 5-year colorectal cancer-specific survival was 81.5%.

CONCLUSION

The incidence of ulcerative colitis-associated colorectal cancer remained constant in our study population over three decades. The prognosis of ulcerative colitis-associated colorectal cancer and the prognosis of sporadic colorectal cancer were comparable. One-third of the cancers were not diagnosed in preoperative colonoscopy, and the indication for surgery in such cases was dysplasia. We therefore do not recommend the endoscopic management of ulcerative colitis-associated dysplasia.

Thyroid Carcinomas That Occur in Familial Adenomatous Polyposis Patients Recurrently Harbor Somatic Variants in APC, BRAF, and KTM2D

Background: Familial adenomatous polyposis (FAP) is a condition typically caused by pathogenic germline mutations in the APC gene. In addition to colon polyps, individuals with FAP have a substantially increased risk of developing papillary thyroid cancer (PTC). Little is known about the events underlying this association, and the prevalence of somatic "second-hit" mutations in APC is controversial. Methods: Whole-genome sequencing was performed on paired thyroid tumor and normal DNA from 12 FAP patients who developed PTC. Somatic mutation profiles were compared with clinical characteristics and previously sequenced sporadic PTC cases. Germline variant profiling was performed to assess the prevalence of variants in genes previously shown to have a role in PTC predisposition. Results: All 12 patients harbored germline mutations in APC, consistent with FAP. Seven patients also had somatic mutations in APC, and seven patients harbored somatic mutations in KMT2D, which encodes a lysine methyl transferase. Mutation of these genes is extremely rare in sporadic PTCs. Notably, only two of the tumors harbored the somatic BRAF p.V600E mutation, which is the most common driver mutation found in sporadic PTCs. Six tumors displayed a cribriform-morular variant of PTC (PTC-CMV) histology, and all six had somatic mutations in APC. Additionally, nine FAP-PTC patients had rare germline variants in genes that were previously associated with thyroid carcinoma. Conclusions: Our data indicate that FAP-associated PTCs typically have distinct mutations compared with sporadic PTCs. Roughly half of the thyroid cancers that arise in FAP patients have somatic "second-hits" in APC, which is associated with PTC-CMV histology. Somatic BRAF p.V600E variants also occur in some FAP patients, a novel finding. We speculate that in carriers of heterozygous pathogenic mutations of tumor suppressor genes such as APC, a cooperating second-hit somatic variant may occur in a different gene such as KTM2D or BRAF, leading to differences in phenotypes. The role of germline variance in genes other than APC (9 of the 12 patients in this series) needs further research.

Restorative Proctocolectomy in Ulcerative Colitis: Effect of Preoperative Immunomodulatory Therapy on Postoperative Complications and Pouch Failure

BACKGROUND AND AIMS

Patients with ulcerative colitis are often treated with multiple immunomodulative agents to achieve remission. In refractory disease, the next option is frequently proctocolectomy with ileal pouch-anal anastomosis. No consensus exists as to whether immunomodulatory therapy at the time of ileal pouch surgery leads to any increase in postoperative complications. Our aim was to assess, in ulcerative colitis patients with restorative proctocolectomy, the effect of preoperative anti-tumor necrosis factor therapy and corticosteroids on postoperative complications and pouch failure.

MATERIALS AND METHODS

A retrospective medical record review of 445 patients with ulcerative colitis who underwent proctocolectomy with ileal pouch-anal anastomosis in Helsinki University Hospital between January 2005 and June 2016.

RESULTS

Anti-tumor necrosis factor agents were not associated with postoperative complications. Only high-dose corticosteroids (prednisolone ⩾20 mg or equivalent) were associated with higher incidence of anastomotic leak (12.6% vs 2.5%, P = 0.002) and wound dehiscence (4.2% vs 0%, P = 0.019), but pouch failure rate was no higher (2.1% vs 0%, P = 0.141) than in patients without corticosteroid treatment. A lower dosage of corticosteroids had no effect on early postoperative complications, but pouch failure rate was increased (4.4% vs 0%, P = 0.015).

CONCLUSION

Corticosteroids, but not anti-tumor necrosis factor therapy, were associated with postoperative complications. Preoperative use of corticosteroids may increase pouch failure rate, but the risk is still minor in high-volume centers performing ileal pouch surgery.

Morbidity related to diverting ileostomy after restorative proctocolectomy in patients with ulcerative colitis

AIM

Restorative proctocolectomy with ileal pouch-anal anastomosis is considered by many surgeons to be the standard procedure for surgical management of ulcerative colitis. There is controversy about whether or not a covering ileostomy should be constructed. The aim of this study was to evaluate the outcomes and morbidity for patients with ulcerative colitis who underwent restorative proctocolectomy with or without a diverting ileostomy.

METHOD

This is a retrospective study of a consecutive series of 510 patients with ulcerative colitis who were operated on in Helsinki University Hospital between January 2005 and June 2016. A diverting ileostomy was performed in 119 patients (the stoma group) compared with 391 patients with no stoma.

RESULTS

Dehydration and intestinal obstruction occurred more often in the stoma group (P < 0.0001). Clinical anastomotic leakage was more common among patients without an ileostomy (6.6% vs 1.7%, P = 0.04). However, the need for re-laparotomy because of any early complication did not differ between the groups (P = 0.58). Within 3 months, 50 patients with ileostomy (42.0%) and 51 patients without (13.0%) were readmitted (P < 0.0001). In total, 35 patients (29.3%) had a complication relating to ileostomy closure and four of them required surgery. There was no difference in the rate of fistulas, pouchitis or pouch failure between the groups.

CONCLUSION

Our study shows that a diverting ileostomy is associated with considerable morbidity but it does not seem to prevent later failure of the pouch. We suggest that a diverting ileostomy should only be constructed for high-risk patients.

Durability of Kock continent ileostomy

PURPOSE

The purpose of this study was to determine the cumulative success rate of Kock continent ileostomy and the reasons leading to excision and to compare the results with pelvic pouch and ileal pouch-anal anastomosis.

METHODS

The data were collected from the histories of 96 patients, who underwent a Kock continent ileostomy operation from 1972 to 2000 at Helsinki University Central Hospital. The failure rate was calculated by the Kaplan-Meier method.

RESULTS

Overall, the continent ileostomy was converted to conventional stoma in 21 patients (24 percent). The cumulative success rate was 96 percent at 1 year, 86 percent at 10 years, 77 percent at 15 years, and 71 percent at 29 years. The most common reason for pouch excision was partial or total nipple-valve sliding. Eighty-five re-reconstructions were performed among 57 patients (59 percent), the most common indication being nipple-valve dysfunction. Of these patients, 14 later ended up with pouch excision. The success rate of continent ileostomy was significantly lower than that of ileoanal anastomosis (P < 0.01).

CONCLUSION

The durability of continent ileostomy is mainly related to the mechanism of the nipple valve and not to ileitis or other systemic effects of the basic disease. Kock continent ileostomy can offer satisfactory long-term function in more than two-thirds of patients up to 30 years.